WarmUp 1 Contrast adaptive radiation vs convergent evolution

Warm-Up 1. Contrast adaptive radiation vs. convergent evolution? Give an example of each. 2. What is the correct sequence from the most comprehensive to least comprehensive taxon? 3. In a population of 500 rabbits, 320 are homozygous dominant for brown coat color (BB), 160 are heterozygous (Bb), and 20 are homozygous white (bb). a. What are the frequencies of the alleles (B and b)? b. What are the frequencies of the different genotypes (BB, Bb, and bb)?

Chapter 26 Phylogeny and the Tree of Life

What you need to know: • The taxonomic categories and how they indicate relatedness. • How systematics is used to develop phylogenetic trees. • The three domains of life including their similarities and their differences.

Systematics: classifying organisms and determining their evolutionary relationships Taxonomy (classification) Systematics Phylogenetics (evolutionary history)

Tools used to determine evolutionary relationships: 1. Fossils 2. Morphology (homologous structures) 3. Molecular evidence (DNA, amino acids) Who is more closely related? Animals and fungi are more closely related than either is to plants.

Taxonomy: science of classifying and naming organisms • Binomial nomenclature (Genus species) Naming system developed by Carolus Linnaeus.

REMEMBER!! • Dear King Philip Came Over For Good Spaghetti • Dear King Philip Crossed Over Five Great Seas • Dear King Philip Came Over From Germany Stoned • Your own? ? ?

Phylogenetic Tree • Branching diagram that shows evolutionary history of a group of organisms

Constructing a Cookie Phylogenetic Tree Video: Bozeman or Simple. Biology

What is the difference between: • Phylogenetic tree and a Cladogram?

Cladogram: diagram that depicts patterns of shared characteristics among taxa • Clade = group of species that includes an ancestral species + all descendents. (*Lines do not = time) • Shared derived characteristics are used to construct cladograms Turtle Leopard Hair Salamander Amniotic egg Tuna Lamprey Lancelet (outgroup) Cladogram Four walking legs Hinged jaws Vertebral column

Monophyletic, paraphyletic, and polyphyletic groups

Constructing a phylogenetic tree A 0 indicates a character is absent; a 1 indicates that a character is present.

Branch lengths can represent genetic change (phylogenetic trees)

Branch lengths can indicate time (Phylo. Trees)

Draw a phylogenetic tree based on the data below. Draw hatch marks on the tree to indicate the origin(s) of each of the 6 characters.

Answer:

What is: • Parsimony? Watch this: https: //www. youtube. com/watch? v=t 0 i. Am. JQcrs

• Principle of maximum parsimony: parsimony use simplest explanation (fewest DNA changes) for tree – “keep it simple” • Molecular clocks: some regions of DNA appear to evolve at constant rates ▫ Estimate date of past evolutionary events ▫ Eg. Origin of HIV infection in humans= 1930’s

Construct a cladogram:

Create a cladogram:

Answer: Closely related-1 and 2. Also, 3 and 4. However, they’re not closely related to each other

More practice needed? • https: //www. youtube. com/watch? v=09 e. D 4 A_H x. VQ • *the site given on your hard copy is down

Various tree layouts Circular (rooted) tree Unrooted tree Rooted tree

Tree of Life • 3 Domains: Bacteria, Archaea, Eukarya

SYSTEMATICS es focus on phylogeny Biological diversity taxonomy cladistics classification Identification of species binomial Genus, species D K P C O F G S Homologous similarities fossils molecular morphology